Street-paving.



UNITED STATES PATENT GEEICE.

l PATRICK J. MORAN, OF MEMPHIS, TENNESSEE.

STREET-PAVING.

SPECIFICATION forming part of Letters IPatent No. 664,024, datedDecember 18, 1900. Application led April 3, 1900. Serial No. 11,376. (Nomodal.)

To a/ZZ whom it may concern:

Be it known that I, PATRICK J. MoEAN, a citizen of the United States,residing at Memphis, Shelby county, State of Tennessee, have inventedcertain new and useful Improvements in Street-Paving, of which thefollowing is a specification.

My invention relates in general to streetpaviug, and more especially tothat class known as concrete paving,in which a bonding materialsuch ascement, asphalt, or the like-is used to bond together the pavingmaterial proper.

Briefly resuming, in the attempt to provide a good paving material manydifferent materials and combinations of materials have been tried withvarying success. Among the first of these are natural gravels having aclay binding material, which are now largely in use, but which becauseof the poor character of the binding materials will not stand excess ofwet or dry weather, and therefore are not entirely satisfactory. Macadamfor the same reason is not a thorough success, and the minds of men havenaturally turned to other fields which follow more or less closely thelines set out by these materials. In the manufacture of compositepavements it has hitherto been customary to use broken or granulatedrock and to bond them together with Portland cement or the like and tofinish oif the surface with a combination of sand and cement to give asmooth surface. This mass, being of unequal composition, cracks andbreaks and is otherwise very unsatisfactory infthat it gives a surfacethat is originally smooth and that underwear becomes more so. Laterattempts to improve these have resulted in the use of linely crushed orpulverized stone as a wearing-surface and in the use of grittysubstances as a top-dressing. vThese while of value for sidewalks haveno value whatsoever as street-paving proper in that they all present asurface that is excessively smooth to horses and gives them no securefoothold whatsoever.

The objects of my invention are to provide a durable wearing-surface forst reet-paving which will at one and the same time be smooth for thewheel-tread and yet aord sucient foothold for horses, one which may belaid with a correct wearing-surface and if not so laid will assume andpreserve same under continuous wear, and one which will give the maximumof use with the minimum of attention and when necessarily disturbed maybe repaired with minimum trouble and expense. I accomplish theseobjectsv by making the pavement of a comparatively hard material ofsensible size interspaced with a relatively soft material and a binder,or with the relatively soft binder alone, the hard material being ofsufficient size to leave, when used with the binder alone, small spacesfilled with the binder, which having small resistance to wear wears downslightly'and gives a surface which is of the nature of good macadam orgravel and presents a well a smooth of large diameter.

larger spaces and a slightly-rougher surface, as will be more fully setout in the general description. I further accomplish these objects byreinforcing the pavement at the points of maximum wear.

Referring now to the drawings, in which like letters of referenceindicate like parts in all the views, Figure lis a sectional perspectiveof a portion of a city street, showing foothold for the horse and assurface for the carriage-wheel Where an additional ma- 'l terial is usedwith the binder, it gives slightlyf sidewalks, curbs, and the streetproper embodying the principal features of my invention. Fig. 2 is asection of the paving on an enlarged scale. Fig. 3 is a like sectionshowing a modification in composition. Fig.:4is a vertical sectionshowing Fig. 3 under'wear. 'In the drawings, A isa section of street,showing my paving. B is a street-car rail; C, the street-curb, and D thesidewalk.'

Since the greatest wear in any street comes near the center of same, Ireinforce same or make it heavier at that point. If the street isunbroken by car-tracks, I make this gradual from the center to thesides. If, however, the street be one, as shown, with street-car rails,I find that the wear is greatest within two to .three feet on theoutside of the cartrack and that from that point out decreases rapidlyfor a short distal then decreases in a much slower ratio to the roo ite.

f ...z tovil lng, I thelfore reinforce it uniformly from the rail B to apoint E about two feet distant therefrom and then make a rapid drop, as

`5 shown, to the top level proper, sloping it thence gradually to thecurb.

Taking up now the construction of the pavement, or rather of thewearing-surface for the pavement, I use a hard stone-such together wit agood grade of `gement, which is preferably Portland. I find that theproportion used in ordinary concrete-viz., six of stone, two of sand,and one of cement-is about the best mixture, and of the stone onehalf totwo-thirds is to be the hard granite and the remainder the softer stone.In Fig. 3 I have shown a section of pavement as first laid, in which Krepresents the soft-stone constituent and L the hard or gran-A In Fig. 4I show the same pavement after hard usage, showing that the granite Lhas Worn comparatively little, while the limestone K has worn sucientlyto give slight depressions G between the adjacent high points H. Theobject of combining these stones of diierent hardness is to providethese slight depressions andto prevent the pavement wearing slick undercontinuous wear. These depressions G are prevented from becomingexcessively deep by the hardness of the adjacent points H of the graniteL. I find, too, that where the crushed granite is sufficiently large(about two and one-half inches) it is possible to secure the' same effect, though not-in so' satisfactory a degree, by binding the granitealone and suicient sand to fill the voids with a good cement binder or,in other words, to make the topdressing for the street ofcoarse-stoneconcrete instead ot' finishing it with a smooth fine-crushedstone and sand-facing, as is now commonly done. In this case thedepressions G, as shown in Fig. 2, are in the cement and sand part ofthe concrete, the high points H being thetops of the granite cubes.

While I have'in this description confined myself to the surface of thepavement only, I prefer to make the pavement homogeneous, as shown-inother words, to use the same size stone bI at the top as those J at thebottom, though this is not necessarily an essential feature of myinvention. In either case this pavement possesses the essential featuresof correct wearing-surface, great strength, im-

' perviousness to water, and is easy t0 repair.

The correct wearing-surface, which is the rst essential, is obtained, asbefore stated,

by the uneven wear of the materials of construction, which uneven weargives slight dease he life of the pav? as g r anite, flint, quartz-rock,iron sla orl hard mms e c can,

.pressions between the hard points'of the hardest material and permitsfoothold for the horses feet. The wear is kept even by the fact thataftera certain amount of depression has been reached the wheels grindonly the projecting material and with the aid of the wear from thehorses feet wear this asr rapidly as the horses feet are able to do thesofter material. This surface is practically as smooth to thelarge-diameter wheel as the best brick, asphalt, or other knownpavement, with the additional advantage of absolute hardness to preventthe sinking ofthe wheel under heavy loads, as in asphalt, by its wavydisplacement or on brick by the bodily displacement of same and at thesame time giving foothold for the horse, thus permitting great increasein the amount of load which can be hauled over it by any given team. Thegreat strength is given by the uniform nature of the material providingequal expansion, but more especially by the--- thorough and strongbonding of the large pieces of stone with the cement and sand, the largepieces giving a thorough an'd interlocking bond between the parts andthe feature of imperviousness to water protecting it practically fromall exposure to action by the atmosphere.

Imperviousness to water is an important factor in that not only is thepaving itself protected from action by the water, but the foundationunderneath is protected both from addition to its moisture' or loss ofwhat it contains by evaporation, a firm foundation for the pavementbeing thus preserved at all times. It is absolutely sanitary in thatnothing offensive can permeate it to remain and throw out its noxiousodors, and by reason of its hardness it can be swept perfectly clean looand all such material removed. Its wear is paving, which is subject tocontinual tear ing u p and replacing in the laying of waterpipes,sewers, &c. In my pavement it is only necessary to recrush the concreteand mix with cement and sand to bond it together, then to tamp it inplace even with the surface of the street, and the work is done, thereplaced portion being practically as good as when first laid and beingequally as impervious to water,and by reason of its strength and perfectbond with the original pavement is in no danger of sinking under heayyloads. In the claim I have used the word stone generically. as includingall classes of material-such as crushed stone, crushed granite, ironslag, gravel, &c.-as distinguished from a narrow specific class.

What I claim, and desire to secure by Letters Patent of the UnitedStates, islp As a surface-layer for street-paving, acon- IIO coarse hardstone and a coarse softer stone, both broken approximately td passthrough a two-and-one-half-inch ring, of a binding naine to thisspecification in the presence of two subscribing witnesses.

' PATRICK J. MORAN.

5 material of sand and cement, mixed in the Witnesses:

proportions o f about three parts each of the 'f C. W. HEISKELL,

stone, tw sandfand'one of ceme t. gELLEY. QW-Sis. ..,cb'7,38791 avlng p,

Murphy@ Q,5o1,sept.9,1879, J' 1 Ambe'rg,291 ,482,Jan.e, 1894,

Paiin,559,821 ,May 28,1895, Stone Pavement sl 'Lee-,1 88,645,Mar,20,v187"f7,lOoncret e Pavement s Mi11s,2:5e,419,Mar.1,1es1

Hicham son,161,55o,nar,:5o,1a75, Paying,encrete,

i Reissue patent to Den,657o,Aug.,13v5, n

Qi MK1n1ey,2v8,o51,nay 22,1585, v v

crete comprising; the combination with a `In testimony whereof I havesigned my

